Hours later, a senior Iranian official said on Sunday that parts of the drone remained intact, despite the fuel having burned much of the drone as it was brought down.

Hajizadeh added that Iranian intelligence had no prior information about the type of drone was shot down.

Hours earlier on Monday, he indicated that Tehran will arm more Palestinians as "revenge" for the drone find. "We will accelerate the arming of the West Bank and we reserve the right to give any response," he said.

Natanz is Iran's main uranium enrichment site, housing more than 16,000 centrifuges. Around 3,000 more are at the Fordow plant, buried inside a mountain and hard to destroy.

Israel has often threatened to attack Iranian nuclear installations; however, it has refused to comment on the veracity of the many reports on the drone incident.